Abstract:

Open trenches are continuous barrier, which are widely installed for efficiently reducing man made vibration. The 2D grid method using displacements variables is flexible and efficient to calculate wave propagation problems, combining the merits of finite elements method and finite difference method. Using the method, the parametric study is conducted herein for vertical vibration isolation by open trenches in layered ground under traffic loading acting on the top of an embankment. The rigid upper layer with soft lower layer ground model and soft upper layer with rigid lower layer ground model are considered respectively. The results show that the width of the open trench has little influence on the screening effectiveness. The depth and location of the open trench are most crucial for the screening effectiveness and they associate each other; so the value of them should be determined comprehensively. The depth of the open trench is equal or close to the thickness of the upper layer is detrimental to the vertical vibration isolation. Higher embankment can give rise to bad influence for vibration isolation in vertical direction.

Key words: grid method, layered ground, open trench, traffic load, vibration isolation